Clinical Use of Testicular Fine Needle Aspiration (FNA) Cytology in Oligospermic and Azoospermic Dogs

Introduction - The diagnostic approach to the subfertile male dogs is complicated by the difficulty in evaluating seminiferous tubule function and semen transport through the excurrent duct system. When dealing with oligo- or azoospermia cases, breeding soundness examination, testicular ultrasonography and serum testosterone assay are often not enough to make a diagnosis; even if FSH assay can be performed, its results may not shed enough light on the case as a low FSH value does not allow to differentiate between a bilateral obstruction of the excurrent duct system and a maturational arrest (two conditions which can be successfully treated but which require different treatments). Because of the fear of irreversably damaging testicles, invasive diagnostic techniques such as testicular biopsy are seldom performed which often hampers the capacity of clinicians to investigate male fertility problems. Fine needle aspiration (FNA) is a less invasive, quick, simple, economic and important technique for immediate evaluation of spermatogenetic alterations widely used in human andrology (1, 2) which has been proposed as a diagnostic tool in dogs (3, 4). Although remarkably less invasive than an open biopsy (4), its diagnostic value is almost as high as that of testicular biopsy (5). The objective of this study was to evaluate clinical relevance of FNA citology in cases of canine male infertility.

Materials and methods - FNA was performed on 7 subfertile dogs (Table n° 1) referred for azoo- or oligozoospermia. A detailed history was collected and the external genitalia examined. [...]